Question

If the nth term of an AP is 5+3 then 4th term of an AP is​

Answer 1

EXPLANATION.

Nth term of an ap : 5 + 3n.

As we know that,

⇒ Tₙ = 5 + 3n.

Put the value of n = 1 in the equation, we get.

⇒ T₁ = 5 + 3(1).

⇒ T₁ = 8.

Put the value of n = 2 in the equation, we get.

⇒ T₂ = 5 + 3(2).

⇒ T₂ = 11.

Put the value of n = 3 in the equation, we get.

⇒ T₃ = 5 + 3(3).

⇒ T₃ = 14.

Put the value of n = 4 in the equation, we get.

⇒ T₄ = 5 + 3(4).

⇒ T₄ = 17.

Series : 8, 11, 14, 17, . . . . .

First term = a = 8.

Common difference = d = b - a = 11 - 8 = 3.

As we know that,

General term of an ap.

⇒ Tₙ = a + (n - 1)d.

Using this formula in this question, we get.

To find : 4th term of an ap.

⇒ T₄ = a + (4 - 1)d.

⇒ T₄ = a + 3d.

Put the values in the equation, we get.

⇒ T₄ = 8 + 3(3).

⇒ T₄ = 8 + 9.

⇒ T₄ = 17.

4th term of an ap : T₄ = 17.